3 files changed, 17 insertions, 7 deletions
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index f9c6e0e3aec7..42411b3ea0c8 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -46,6 +46,16 @@ struct drm_device {
 	struct drm_master *master;
 
 	/**
+	 * @driver_features: per-device driver features
+	 *
+	 * Drivers can clear specific flags here to disallow
+	 * certain features on a per-device basis while still
+	 * sharing a single &struct drm_driver instance across
+	 * all devices.
+	 */
+	u32 driver_features;
+
+	/**
 	 * @unplugged:
 	 *
 	 * Flag to tell if the device has been unplugged.
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 698082a02b97..2a3843f248cf 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1261,12 +1261,12 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
  */
 enum drm_dp_quirk {
 	/**
-	 * @DP_DPCD_QUIRK_LIMITED_M_N:
+	 * @DP_DPCD_QUIRK_CONSTANT_N:
 	 *
 	 * The device requires main link attributes Mvid and Nvid to be limited
-	 * to 16 bits.
+	 * to 16 bits. So will give a constant value (0x8000) for compatability.
 	 */
-	DP_DPCD_QUIRK_LIMITED_M_N,
+	DP_DPCD_QUIRK_CONSTANT_N,
 };
 
 /**
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 23b9678137a6..8830e3de3a86 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -653,14 +653,14 @@ static inline bool drm_dev_is_unplugged(struct drm_device *dev)
  * @dev: DRM device to check
  * @feature: feature flag
  *
- * This checks @dev for driver features, see &drm_driver.driver_features and the
- * various DRIVER_\* flags.
+ * This checks @dev for driver features, see &drm_driver.driver_features,
+ * &drm_device.driver_features, and the various DRIVER_\* flags.
  *
  * Returns true if the @feature is supported, false otherwise.
  */
-static inline bool drm_core_check_feature(struct drm_device *dev, int feature)
+static inline bool drm_core_check_feature(struct drm_device *dev, u32 feature)
 {
-	return dev->driver->driver_features & feature;
+	return dev->driver->driver_features & dev->driver_features & feature;
 }
 
 /**